/* -*- mode: C -*-  */
/* 
   IGraph library.
   Copyright (C) 2007-2012  Gabor Csardi <csardi.gabor@gmail.com>
   334 Harvard st, Cambridge MA, 02139 USA
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc.,  51 Franklin Street, Fifth Floor, Boston, MA 
   02110-1301 USA

*/

#include <igraph.h>

int print_mincut(const igraph_t *graph, igraph_real_t value, 
		 const igraph_vector_t *partition, 
		 const igraph_vector_t *partition2, 
		 const igraph_vector_t *cut, 
		 const igraph_vector_t *capacity) {
  
  long int i, nc=igraph_vector_size(cut);
  igraph_bool_t directed=igraph_is_directed(graph);

  printf("mincut value: %g\n", (double) value);
  printf("first partition:  ");  igraph_vector_print(partition);
  printf("second partition: ");  igraph_vector_print(partition2);
  printf("edges in the cut: ");
  for (i=0; i<nc; i++) {
    long int edge=VECTOR(*cut)[i];
    long int from=IGRAPH_FROM(graph, edge);
    long int to  =IGRAPH_TO  (graph, edge);
    if (!directed && from > to) {
      igraph_integer_t tmp=from;
      from=to;
      to=tmp;
    }
    printf("%li-%li (%g), ", from, to, VECTOR(*capacity)[edge]);
  }
  printf("\n");
  
  return 0;
}

int main() {
  
  igraph_t g;
  igraph_vector_t weights, partition, partition2, cut;
  igraph_real_t value;

  igraph_vector_init(&partition, 0);
  igraph_vector_init(&partition2, 0);
  igraph_vector_init(&cut, 0);

  /* -------------------------------------------- */
  
  igraph_small(&g, 0, IGRAPH_UNDIRECTED, 
	       0,1, 0,4, 1,2, 1,4, 1,5, 2,3, 2,6, 3,6, 3,7, 4,5, 5,6, 6,7,
	       -1);
  igraph_vector_init_int_end(&weights, -1, 2,3,3,2,2, 4,2,2,2,3, 1,3, -1);
  
  igraph_mincut(&g, &value, &partition, &partition2, &cut, &weights);
  print_mincut(&g, value, &partition, &partition2, &cut, &weights);
  
  igraph_vector_destroy(&weights);
  igraph_destroy(&g);

  /* -------------------------------------------- */

  igraph_small(&g, 6, IGRAPH_DIRECTED,
	       0,1,1,2,2,3, 0,5,5,4,4,3, 3,0, -1);
  igraph_vector_init_int_end(&weights, -1, 3,1,2, 10,1,3, 2, -1);

  igraph_mincut(&g, &value, &partition, &partition2, &cut, &weights);
  print_mincut(&g, value, &partition, &partition2, &cut, &weights);

  igraph_vector_destroy(&weights);
  igraph_destroy(&g);

  /* -------------------------------------------- */

  igraph_small(&g, 5, IGRAPH_DIRECTED,
	       4,3, 3,2, 2,1, 1,0, 
	       -1);
  igraph_vector_init_int_end(&weights, -1, 1,1,1,1, -1);
  igraph_mincut(&g, &value, &partition, &partition2, &cut, &weights);
  print_mincut(&g, value, &partition, &partition2, &cut, &weights);

  igraph_vector_destroy(&weights);
  igraph_destroy(&g);

  /* -------------------------------------------- */

  igraph_vector_destroy(&cut);
  igraph_vector_destroy(&partition2);
  igraph_vector_destroy(&partition);
 
  return 0;
}
